1. Technical Field
The present invention is directed toward cellular telephones, and more particularly toward an accessory for a cellular telephone.
2. Background Art
"Handsfree capability" for a cellular telephone is a feature which allows a user to operate a cellular telephone without requiring the user to hold the cellular telephone up to their head. Volume levels from the telephone are amplified allowing the user to hear sound emanating from the cellular telephone, and a microphone with greater sensitivity is used to receive the user's voice during a conversation. Handsfree capability in a cellular telephone yields advantages by freeing-up the hands of a user while the user is operating the cellular telephone. This leads to increased safety where a user is driving an automobile while operating a cellular telephone, and added convenience while a user is using a cellular telephone while attempting other work.
A "car cradle kit" allows handsfree operation by placing the cellular telephone into a `cradle` which connects an external speaker and microphone to the system connector port for the cellular telephone. A user is then able to communicate to and receive communications from a party to which the cellular telephone is connected. However, the car cradle kit requires a power supply separate from the cellular telephone, and is not usable without the separate power supply. Further, car cradle kits are installed in a fixed location (e.g., a car) so that they are usable only at the installation location.
A cellular telephone that has been made with built-in handsfree capability uses the speaker and microphone present in the cellular telephone to communicate to and from a party to which the cellular telephone is connected. This cellular telephone has an infrared device which detects the distance of the cellular telephone from the user, and adjusts the volume of the telephone speaker accordingly. However, a malfunction with the infrared device could result in damage to the hearing of the cellular telephone's user.
Many cellular telephones also contain a gasket between the speaker and the microphone which isolate the speaker vibrations from the microphone to prevent feedback. This is particularly a problem with telephones with handsfree capability, given the higher speaker volumes and microphone sensitivity.
Additionally, most cellular telephones have an audible alert for an incoming telephone call. Such cellular telephones are difficult to use in both quiet and noisy areas. In areas where quiet is desired, such as a movie theater, a library, or a church, a user may turn the cellular telephone off to avoid offending others around them. In areas where it is noisy such as in a room crowded with people or an outdoor sporting event, a user may not hear the audible alert. In both situations, the user risks missing calls to the cellular telephone.